1. Field of the Invention
This invention relates to various carbamate additives for lubricating compositions. More specifically, this invention relates to carbamate additives derived from the reaction of an amine with carbon disulfide and a reactant containing an activated, ethylenically unsaturated bond or an alpha-chloro or alpha-bromo carboxylic acid or derivative thereof. These additives impart improved extreme pressure and anti-wear properties to lubricating compositions, particularly lubricating compositions which are phosphorus-free or contain a very low phosphorus concentration.
2. State of the Art
Carbamate compounds derived from reactants containing activated, ethylenically unsaturated bonds which have a number of different utilities are known in the art. For example, U.S. Pat. No. 2,067,494 discloses various dithiocarbamates which are useful for accelerating the vulcanization of rubber.
U.S. Pat. No. 2,710,872 discloses dithiocarbamic acids and esters thereof which are useful as intermediates in the production of pharmaceuticals, bactericides, insecticides and anti-oxidants for lard.
In U.S. Pat. No. 2,841,530, various salts of dithiocarbamates are disclosed as being useful in the preparation of hair waving compositions.
U.S. Pat. No. 2,897,152 discloses turbine oils comprising a specific class of dithiocarbamate additives to impart extreme pressure properties in the oil.
In U.S. Pat. No. 3,211,711 2-cyanovinyl dithiocarbamates are disclosed for use in pesticide compositions.
In U.S. Pat. Nos. 3,890,363 and 3,833,496, a specific class of dithiocarbamate compounds is disclosed as useful anti-oxidant and anti-wear additives for use in lubricating oils and greases.
U.S. Pat. No. 4,130,578 discloses various (alkoxycarbonyl) alkyl esters of dithiocarbanilic acid, which are useful as immunoregulatory agents for treatment of organ transplant rejection and other immune diseases.
U.S. Pat. No. 4,064,265 discloses dithiocarbamic acid esters useful as anthelmintics.
In U.S. Pat. No. 4,254,142, norbornylthio- and dithiocarbanilic acids are disclosed as being useful as immunosuppressive agents.
U.S. Pat. No. 4,161,534 discloses phenyloxyphenyl or phenylaminophenyl substituted dithiocarbamates which are useful as anthelmintic agents.
U.S. Pat. No. 4,202,832 discloses various thiocarbamoylthio fatty acid derivatives which are useful as lipid-lowering agents.
None of the foregoing disclosures, however, teach the class of carbamate additives of the present invention which are useful as additives for lubricating compositions.